Thursday, October 18, 2012

Often, new treatments are no better than old ones

- Kenny Lin, MD

A recent systematic review and meta-analysis from the Cochrane Collaboration broke new ground in evaluating not one intervention or group of interventions for a single health condition, but the more general question of whether new treatments are more effective than established ones. The authors analyzed data from four cohorts of publicly funded trials of cancer treatments, treatments for neurological problems, and treatments for mixed diseases. In this sample, they found that slightly more than half of new treatments turned out to be better than old ones, but not by much: primary outcomes were just 9 percent better with the new treatments, and mortality fell by only 5 percent.

To make it easier for family physicians to compare new treatments to old ones, AFP publishes the STEPS (Safety, Tolerability, Effectiveness, Price, and Simplicity) series of new drug reviews. The October 15th issue includes a STEPS review of rivaroxaban (Xarelto), a new oral anticoagulant that is indicated to reduce the risk of stroke and systemic embolism in patients with atrial fibrillation. Under Effectiveness, the review notes: "Rivaroxaban was as effective as warfarin at preventing stroke and systemic embolism, and reduced annual stroke rates to 2.1 percent, compared with 2.4 percent for warfarin. No trials have compared rivaroxaban with dabigatran (Pradaxa), a direct thrombin inhibitor, or with fondaparinux (Arixtra), an injectable factor Xa inhibitor." Rivaroxaban does not require laboratory INR monitoring like warfarin, but costs more than 40 times as much. Family physicians and patients will need to decide whether this relatively small benefit is worth the increased cost of this new drug compared to the old.